Energy delivery conduits for use with electrosurgical devices

ABSTRACT

A conduit assembly for transmitting energy between an electrosurgical energy generator and an energy delivering device comprises a first cable sub-assembly including a cable having a flexibility and an energy attenuation; a second cable sub-assembly including a cable having a flexibility and an energy attenuation; wherein the flexibility of the cable of the first cable sub-assembly is less than the flexibility of the cable of the second cable sub-assembly; and wherein the energy attenuation of the cable of the first cable sub-assembly is less than the energy attenuation of the cable of the second cable sub-assembly.

The present application is a continuation application, which claimspriority to, and the benefit of, U.S. patent application Ser. No.11/805,052, filed on May 22, 2007, the disclosure of which is hereinincorporated by reference in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to electrosurgical systems, and moreparticularly, to energy delivery conduits for use with electrosurgicaldevices during RF and/or microwave ablation procedures.

2. Background Of Related Art

Energy delivery conduits, including coaxial cables are well known in theart and its applications are numerous. Coaxial cables are typicallyused, in surgical procedures, to transfer energy from one point toanother while minimizing losses during said transmission.

Although many kinds of coaxial cables have been designed, for the mostpart, these devices serve primarily as energy transmission conduits.Aside from transmitting energy, it is often desirable to have coaxialcables with different characteristics and features.

SUMMARY

The present disclosure relates to a conduit assembly for transmittingelectrosurgical energy between an electrosurgical generator and anenergy delivering device. The conduit assembly comprises a first cablesub-assembly including a cable; and a second cable sub-assemblyincluding a cable. The flexibility of the cable of the first cablesub-assembly is less than the flexibility of the cable of the secondcable sub-assembly. Further, the energy attenuation of the cable of thefirst cable sub-assembly is less than the energy attenuation of thecable of the second cable sub-assembly. In one embodiment, the diameterof the first cable sub-assembly is larger than the diameter of thesecond cable sub-assembly. In another embodiment, the length of thefirst cable sub-assembly is greater than the length of the second cablesub-assembly.

The conduit assembly may further include a connector assembly. Theconnector assembly includes a first connector operatively connected to afirst end of the cable of the first cable sub-assembly and a secondconnector operatively connected to the second end of the cable of thesecond cable sub-assembly. The first and second connecters are matablewith one another to electrically connect the cable of the first cablesub-assembly with the cable of the second cable sub-assembly.

Additionally, the cable of the first cable sub-assembly includes aninner conductor surrounded by a dielectric material and an outerconductor surrounding the dielectric material. The cable of the secondcable sub-assembly also includes an inner conductor surrounded by adielectric material and an outer conductor surrounding the dielectricmaterial.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the presently disclosed conduit assemblies are disclosedherein with reference to the drawings, wherein:

FIG. 1 is a perspective view of a conduit assembly according to anembodiment of the present disclosure shown attached between an energydelivering device and an electrosurgical energy generator;

FIG. 2 is a side elevational view of a first cable assembly of theconduit assembly of FIG. 1;

FIG. 3 is a longitudinal cross-sectional view of a portion of the firstcable assembly of the conduit cable assembly of FIGS. 1 and 2, as takenthrough 3-3 of FIG. 2;

FIG. 4 is a side elevational view of second cable assembly of theconduit assembly of FIGS. 1-3;

FIG. 5 is a longitudinal cross-sectional view of the second cableassembly of the conduit assembly of FIGS. 1-3, as taken through 5-5 ofFIG. 4;

FIG. 6 is a perspective view of a conduit assembly according to anotherembodiment of the present disclosure;

FIG. 7 is a perspective view of a conduit assembly according to stillanother embodiment of the present disclosure;

FIG. 8 is a side elevational view of a conduit assembly according to afurther embodiment of the present disclosure shown attached between anenergy delivering device and an electrosurgical energy generator; and

FIG. 9 is a longitudinal cross-sectional view of a portion of theconduit assembly of FIG. 8, as taken through 9-9 of FIG. 8.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed energy transmission conduitassembly are now described in detail with reference to the drawings, inwhich like reference numerals designate identical or correspondingelements in each of the several views. As used herein, the terms“distal” refers to that portion of the conduit assembly, or componentthereof, farther from the user while the term “proximal” refers to thatportion of the component thereof, closest to the user.

Electrosurgical energy delivering systems employ electrosurgical energy(e.g., RF or microwave) to ablate tissue at a specific target site.During electrosurgical procedures, electrosurgical energy deliveringsystems directly apply therapeutic energy to a desired tissue locationto ablate said tissue.

Electrosurgical energy delivering systems include an electrosurgicalenergy generator “G” (i.e., RF and/or microwave generator), an energydelivery device or instrument “D” having a probe, needle, antenna,and/or knife and at least one energy delivery conduit interconnectingthe energy delivering device “D” and the generator “G”.

The energy transmission conduit assembly hereinbelow described isintended to be used with a microwave energy delivering system. It iscontemplated, however, that the energy transmission conduit assemblydescribed below may be utilized with any suitable electrosurgical systemknown in the art. The described energy transmission conduit assembly isdesigned to minimize loss of energy along or throughout a lengththereof.

Referring initially to FIGS. 1-5, an energy transmission conduitassembly in accordance with an embodiment of the present disclosure, isgenerally referred to as reference numeral 100. Conduit assembly 100includes a first cable sub-assembly 104 configured and adapted forconnection to an electrosurgical energy generator “G” via a generatorconnector 102, a second cable sub-assembly 108 configured and adaptedfor connection to an energy delivering device “D” via a device connector110, and a cable connector assembly 106 configured and adapted tointerconnect first cable sub-assembly 104 and second cable sub-assembly108 to one another.

As seen in FIG. 2, first cable sub-assembly 104 includes a cable 105configured to transmit electrosurgical energy, a generator connector 102operatively connected to a first end of cable 105 and configured andadapted for connection to generator “G”, and a first connector 106a ofcable connector 106 operatively connected to a second end of cable 105.

Generator connector 102 may include an insulative or dielectric covering102a such as a polyolefin heat-shrink tubing, as depicted in FIG. 2.Other suitable dielectric materials, known by those having skill in theart, may be used to electrically insulate generator connector 102. Inaddition to generator connector 102, adapters (not shown) may be used tointerconnect electrosurgical energy generator “G” to first cablesub-assembly 104 if generator connector 102 is not properly sized ordoes not properly mate with electrosurgical energy generator “G”.

With reference to FIG. 3, cable 105 of first cable sub-assembly 104comprises an inner conductor 112 surrounded by a dielectric material114, and an outer conductor 116 surrounding dielectric material 114 andencompassed by an outer sheath 118. Dielectric material 114 may beformed of any suitable low energy loss material such as low density orultra-density PolyTetraFluoroEthylene (“PTFE”), cellular high densitypolyethylene or the like. Outer sheath 118 may be comprised of anysuitable electrically insulative material known in the art such asfluorinated ethylene propylene (“FEP”) or polyolefin.

It is contemplated that cable 105 of first cable sub-assembly 104 may beflexible or semi-rigid. Accordingly, inner conductor 112 of cable 105may be flexible (i.e., having a stranded transverse cross-sectionalprofile or any other suitable flexible structure known in the art) orsemi-rigid (i.e., having a solid transverse cross-section profile or anyother semi-rigid structure known in the art). Outer conductor 116 may beflexible (i.e., made of braided silver plated cooper or any othersuitable material known in the art) or semi-rigid (i.e., be fabricatedof solid cooper or any other suitable material known in the art).

Inner conductor 112 of first cable sub-assembly 104 may be fabricatedfrom cooper or from any other suitable electrically conductive material.Additionally, inner conductor 112 may contain a conductive plating orthe like. The conductive plating may be comprised of silver or othersuitable material known in the art.

Cable 105 of first cable sub-assembly 104 may be long enough to allow asurgeon to extend it from electrosurgical energy generator “G” to thepatient in a typical medical suite, while at the same time, short enoughto limit energy attenuation therealong. Specifically, it is envisionedthat the length of cable 105 may range from about 5 feet to about 10feet. It is further contemplated that cable 105 may have a diametergreater than about 0.14 inches. In one embodiment, the diameter of cable105 may measure approximately 0.20 inches.

In an alternative embodiment, cable 105 of first cable assembly 104 maybe enclosed in an articulating arm that extends into and over thesterile field. The articulating arm may be part of the electrosurgicalenergy generator “G” or, a separate cart system. Alternatively, cable105 may be detachably connected to the electrosurgical energy generator“G” via a fastening device such as a removable clip (not shown). Thefastening device may prevent cable 105 from exerting excessive force onthe energy delivering device “D”. Cable 105 and/or first cablesub-assembly 104 may be reusable or disposable.

Referring now to FIGS. 1 and 4, second cable sub-assembly 108 includes acable 109 configured to transmit electrosurgical energy, a deviceconnector 110 connected to a first end of cable 109 for connection toenergy delivering device “D” and a second connector 106 b of cableconnector 106 operatively connected to a second end of cable 109configured and adapted for selective coupling with first connector 106 aof first cable sub-assembly 104. Device connector 110 may includeadapters (not shown) to properly mate with energy delivering device “D”or second cable assembly 108.

With reference to FIG. 5, cable 109 of second cable sub-assembly 108comprises an inner conductor 120 surrounded by a dielectric material122, and an outer conductor 124 surrounding dielectric material 122 andencompassed by an outer sheath 126. Outer conductor 124 and innerconductor 120 are configured as a coaxial cable. Inner conductor 120 ofsecond cable sub-assembly 108 has a smaller diameter than innerconductor 112 of first cable sub-assembly 104. Likewise, outer conductor124 of second cable sub-assembly 108 has a smaller diameter than outerconductor 116 of first cable sub-assembly 104. Second cable sub-assembly108 may be reusable or disposable.

It is envisioned that cable 109 of second cable sub-assembly 108 may beflexible. Accordingly, inner conductor thereof 120 may be flexible andmay have a stranded transverse cross-sectional profile. Copper or othersuitable electrically conductive material may be utilized to make innerconductor 120. In an embodiment, inner conductor 120 may include asilver plating.

The length of cable 109 of second cable assembly 108 may be short enoughto limit energy attenuation, but sufficiently long to allow goodmaneuverability of energy delivering device “D”. It is envisioned thatthe length of cable 109 of second cable sub-assembly 108 may range fromabout 0.5 feet to about 2.0 feet. In one embodiment, the length of cable109 of second cable sub-assembly 108 may measure about 12 inches. It isfurther contemplated that cable 109 of second cable sub-assembly 108 mayhave a diameter less than about 0.12 inches. In one embodiment, thediameter of cable 109 of second cable sub-assembly 108 may measure about0.10 inches.

Dielectric material 122 of second cable sub-assembly 108 may be made ofany suitable low loss dielectric material such as low density orultra-low density PTFE, or cellular high density polyethylene. Outerconductor 124 of second cable sub-assembly 108 may be formed of braidedsilver plated cooper or any other suitable electrically conductivematerial known in the art.

In use, connectors 102, 106, 110 electrically connect electrosurgicalenergy generator “G”, first and second cable sub-assemblies 104, 108 ofconduit assembly 100, and energy delivering device “D” to one another.To facilitate electrical conductivity throughout and along conduitassembly 100, connectors 102, 106, 110 may have an impedance appropriatefor the specific electrosurgical system employed. It is envisioned thateach connectors 102, 106, 110 may have an impedance of about 50 Ohms. Inaddition, an electrically insulative material, such as polylefin, PVC orplastic heat-shrink tubing, may be placed over connectors 102, 106, 110to provide electrical insulation thereof, as illustrated in FIG. 2. Aperson skilled in the art will understand that many other kinds ofsuitable dielectric materials may be used to cover connectors 102, 106,110.

Returning now to FIG. 2, the distal or first end of first cablesub-assembly 104 is connected to the proximal or second end of secondcable sub-assembly 108 via first and second connectors 106 a, 106 b ofcable connector 106. Adaptors may supplement cable connector 106 in theevent that cable connector 106 does not properly mate with either firstcable sub-assembly 104 or second cable sub-assembly 108. Alternatively,first cable sub-assembly 104 may be connected directly to second cablesub-assembly 108 through crimping, soldering, welding or any othersuitable method as known by one skilled in the art. It will be apparentto one skilled in the art that second cable sub-assembly 108 may beconnected to the energy delivering device “D” by any suitable methodsuch as crimping, soldering, or welding.

In an alternative embodiment, the electrical connection between innerconductor 112 of first cable sub-assembly 104 and inner conductor 120 ofsecond cable sub-assembly 108 may be achieved by crimping the innerconductor 120 over first inner conductor 112. If cable 105 of firstcable sub-assembly 104 has a stranded inner conductor 112, electricalconnection may be achieved by crimping the stranded inner conductor 112over the inner conductor 120 of second cable sub-assembly 108.Electrical connection between outer conductors 116 of first cablesub-assembly 104 and outer conductor 124 of second cable sub-assembly108 may be achieved by crimping first outer conductor 116 over secondouter conductor 124, irrespective of their form.

In one embodiment, electrical connection between inner conductors 112,120 may be achieved by soldering and/or welding the two inner conductors112, 120 together. Outer conductors 116, 124 may also be soldered and/orwelded together to achieve electrical connectivity therebetween. It iscontemplated that a combination of crimping, soldering and welding maybe used to connect inner conductors 112, 120 to one another and outerconductors 116, 124 to one another.

Conduit assembly 100 may have cable sub-assemblies having cables ofvarious lengths with various energy attenuation levels. Alternatively,conduit assembly 100, having the same energy loss levels, may havecables of different sizes, diameters and/or lengths. It is envisionedthat the conduit assembly 100 may have a maximum energy loss of about −3dB at about 915 MHz.

In one embodiment, conduit cable assembly 100 may include first cablesub-assembly 104 having a cable 105 with a length of about 9 feet. Cable105 is connected through cable connector 106 to a cable 109 of secondcable sub-assembly 108 having a length of about 1 foot. Conduit cableassembly 100 also includes a generator connector 102 disposed at aproximal end thereof. As previously discussed, generator connector 102is configured and adapted for connection to electrosurgical energygenerator “G”. Generator connector 102 may include an insulative ordielectric covering 102 a such as a polyolefin heat-shrink tubing. Adevice connector 110 is disposed at the distal end of the conduitassembly 100 and is configured and adapted for connection toelectrosurgical energy delivery device “D”. Cable 105 may have an energyattenuation of about −0.14 dB/foot at about 915 MHz. In turn, cable 109may have an energy attenuation of about −0.25 dB/foot at about 915 MHz.Each connector 102, 106, 110 may have an energy attenuation of about−0.07 dB at about 915 MHz. In this embodiment, the total energyattenuation at about 915 MHz may be about −1.79 dB. This embodiment maybe used particularly for percutaneous applications.

In a further embodiment, conduit assembly 100 has a first cablesub-assembly 104 having a cable 105 with a length of about 6 feet. Cable105 is connected through cable connector 106 to a cable 109 of secondcable sub-assembly 108 having a length of about 1 foot. Conduit assembly100 may have a generator connector 102 disposed at the proximal endthereof and a device connecter 110 disposed at the distal end thereof.Generator connector 102 is configured and adapted for connection to anelectrosurgical energy generator “G”. Device connector 110 is configuredand adapted for connection to an energy delivering device “D.” In thisembodiment, cable 105 has an energy attenuation of about −0.14 dB/footat about 915 MHz. Cable 109 has an energy attenuation of about −0.25dB/foot at about 915 MHz. Each connector 102, 106, 110 may have anenergy attenuation of about 0.07 dB at about 915 MHz. The total energyattenuation in this embodiment may be about −1.37 dB. This embodimentmay be used particularly for surgical applications. While the figures ofthe present disclosure illustrate a conduit assembly 100 with only twocables, it is contemplated that more than two cables may be used toattain the desired combination of energy attenuation and assemblyflexibility.

In use, first cable sub-assembly 104 allows transmission ofelectrosurgical energy from electrosurgical energy generator “G” tosecond cable sub-assembly 108. Cable connector 106 interconnects firstcable sub-assembly 104 and second cable sub-assembly 108. To achieve lowenergy losses, the impedance of cable 105 of first cable sub-assembly104 must be appropriate for the specific electrosurgical system used.For example, in one embodiment, first cable 105 of first cablesub-assembly 104 has an impedance of about 50 Ohms.

Moreover, cable 105 of second cable sub-assembly 108 has a higher degreeof flexibility than cable 109 of first cable sub-assembly 104. However,cable 105 of first cable sub-assembly 108 has lower energy attenuationthan cable 109 of second cable sub-assembly 104. Such a design providesconduit assembly 100 with good maneuverability, while at the same time,limits energy losses between electrosurgical energy generator “G” andenergy delivering device “D”.

In operation, energy delivering device “D” is connected toelectrosurgical energy generator “G” through conduit assembly 100 andreceives electrosurgical energy from energy generator “G”. Duringoperation, conduit assembly 100 minimizes the energy attenuation alongits length, thereby maximizing the energy transmitted to energydelivering device “D”, and limiting heating of conduit assembly 100.Moreover, the flexibility of conduit assembly 100 allows a surgeon toeasily maneuver energy delivering device “D” during clinical procedures.

Turning now to FIGS. 8 and 9, a conduit assembly according to anotherembodiment of the disclosure is generally designated as 200. Conduitassembly 200 is substantially similar to conduit assembly 100 and thuswill only be discussed in detail herein to the extent necessary toidentify differences in construction and operation.

As seen in FIGS. 8 and 9, conduit assembly 200 comprises a single cable205 having a variable diameter along its length. Cable 205 includes afirst or proximal section 204, a transition section 205 a and a secondor distal section 208. First section 204 has a diameter greater than adiameter of second section 208. Accordingly, a flexibility of secondsection 208 may be relatively higher than a flexibility of first section204. In addition, first section 204 may have a relatively lower energyattenuation than second section 208.

Transition section 205 a varies in diameter between first section 204and second section 208. A proximal end of transition section 205 a has adiameter equal to the diameter of first section 204. A distal end oftransition section 205 a has a diameter equal to the diameter of secondsection 208.

First section 204 is connectable to an electrosurgical energy generator“G” via a generator connector 202. Generator connector 202 may includean insulative or dielectric covering 202 a such as a polyolefinheat-shrink tubing. Second section 208, in turn, is connectable to anenergy delivering device “D” via device connector 210.

As seen in FIG. 9, cable 205 comprises an inner conductor 212 surroundedby a dielectric material 214, an outer conductor 216 surroundingdielectric material 214, and an outer sheath 218 encompassing outerconductor 216. Inner conductor 212 includes a first section 212 a havinga first diameter, a second section 212 b having a second diameter, andtransition section 212 c interconnecting the first and second sections212 a, 212 b.

It is envisioned that cable 205 may be flexible or semi-rigid.Accordingly, inner conductor 212 of cable 205 may be flexible (i.e.,having a stranded transverse cross-sectional profile or any othersuitable flexible structure known in the art) or semi-rigid (i.e.,having a solid transverse cross-sectional profile or any othersemi-rigid structure known in the art). Cooper or other suitableelectrically conductive material may be utilized to make inner conductor212. Inner conductor 212 may also include silver plating. Outerconductor 216 may be flexible (i.e., made of braided silver platedcooper or any other suitable material known in the art) or semi-rigid(i.e., be fabricated of solid cooper or any other suitable materialknown in the art).

Dielectric material 214 may be formed of any suitable low energy lossmaterial such as low density or ultra-density PolyTetraFluoroEthylene(“PTFE”), cellular high density polyethylene or the like. Outer sheath218 may be comprised of any suitable electrically insulative materialknown in the art such as fluorinated ethylene propylene (“FEP”) orpolyolefin. Conduit assembly 200 may have, for example, a total energyloss of about −1.79 dB or −1.37 dB.

Energy delivering device “D” may be used for surgical proceduresentailing microwave ablation. However, the applications of the conduitassemblies and methods of using the conduit assemblies, discussed above,are not limited thereto, but may include any number of furtherelectrosurgical applications. Modifications of the above-describedconduit assembly and the same, and variations of aspects of thedisclosure that are obvious to those of skill in the art are intended tobe within the scope of the claims.

What is claimed is:
 1. A conduit assembly for transmittingelectrosurgical energy between an electrosurgical generator and anenergy-delivery device, the conduit assembly comprising: a first cablesub-assembly including a cable having an energy attenuation; and asecond cable sub-assembly including a cable having an energyattenuation; wherein the energy attenuation of the cable of the firstcable sub-assembly is less than the energy attenuation of the cable ofthe second cable sub-assembly.
 2. The conduit assembly according toclaim 1, wherein the cable of the first cable sub-assembly has adiameter and the cable of the second cable sub-assembly has a diameterless than the diameter of the cable of the first cable sub-assembly. 3.The conduit assembly according to claim 1, wherein the cable of thefirst cable sub-assembly has a length, and the cable of the second cablesub-assembly has length less than the length of the cable of the firstcable sub-assembly.
 4. The conduit assembly according to claim 2,wherein the cable of the second cable sub-assembly has a flexibility,and the cable of the first cable sub-assembly has flexibility less thanthe flexibility of the cable of the second cable sub-assembly.
 5. Theconduit assembly according to claim 1, further comprising a connectorassembly having a first connector operatively connected to a first endof the cable of the first cable sub-assembly and a second connectoroperatively connected to a second end of the cable of the second cablesub-assembly, wherein the first and second connectors are matable withone another to electrically connect the cable of the first cablesub-assembly with the cable of the second cable sub-assembly.
 6. Theconduit assembly according to claim 1, wherein the cable of the firstcable sub-assembly includes an inner conductor surrounded by adielectric material, and an outer conductor surrounding the dielectricmaterial; and wherein the cable of the second cable sub-assemblyincludes an inner conductor surrounded by a dielectric material, and anouter conductor surrounding the dielectric material.
 7. The conduitassembly according to claim 6, wherein the outer conductor of the secondcable sub-assembly is surrounded by an outer sheath to prevent usercontact therewith.
 8. The conduit assembly according to claim 1, whereinthe conduit assembly has an energy loss of about −1.79 dB.
 9. Theconduit assembly according to claim 1, wherein the conduit assembly hasan energy loss of about −1.37 dB.
 10. The conduit assembly according toclaim 1, wherein the cable of the first cable sub-assembly includes agenerator connector adapted to connect the proximal end of the cable ofthe first cable sub-assembly and the electrosurgical generator.
 11. Theconduit assembly according to claim 1, wherein the cable of the secondcable sub-assembly includes a device connector adapted to connect thedistal end of the cable of the second cable sub-assembly and theenergy-delivery device.
 12. A conduit assembly for transmitting energy,comprising: a first cable sub-assembly including proximal and distalends, the proximal end adapted for connection to an electrosurgicalenergy generator, the first cable sub-assembly including: a first cableincluding: a first inner conductor; a first outer conductor disposedcoaxially around the first inner conductor; and a first dielectricmaterial disposed between the first inner conductor and the first outerconductor; wherein the first cable has a first energy attenuation; asecond cable sub-assembly including proximal and distal ends, theproximal end adapted for interconnecting the first cable sub-assemblyand the second cable sub-assembly, and the distal end configured to beoperatively connected to an energy-delivery device, the second cablesub-assembly including: a second cable including: a second innerconductor ; and a second outer conductor disposed coaxially around thesecond inner conductor; wherein the second cable has a second energyattenuation; and wherein the second energy attenuation is greater thanthe first energy attenuation.
 13. The conduit assembly according toclaim 12, wherein the first cable has a first diameter and the secondcable has a second diameter.
 14. The conduit assembly according to claim13, wherein the first diameter is greater than the second diameter. 15.The conduit assembly according to claim 12, wherein the first innerconductor includes a conductive plating surrounding the first innerconductor.
 16. The conduit assembly according to claim 12, wherein thesecond inner conductor includes a conductive plating surrounding thefirst inner conductor.
 17. The conduit assembly according to claim 12,further comprising a first connector interconnecting the distal end ofthe first cable sub-assembly and the proximal end of the second cablesub-assembly.
 18. The conduit assembly according to claim 12, whereinthe first cable has a flexibility, and the second cable has aflexibility.
 19. The conduit assembly according to claim 18, wherein theflexibility of the first cable is less than the flexibility of thesecond cable.
 20. The conduit assembly according to claim 12, whereinthe second outer conductor is surrounded by an outer sheath to preventuser contact therewith.